Paroxysmal nocturnal dyspnea
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How is paroxysmal nocturnal dyspnea diagnosed?

Paroxysmal nocturnal dyspnea (PND) is an attack of severe shortness of breath and coughing that generally occurs at night. It usually occurs several hours after the person has fallen asleep and improves when he sits upright. 

PND can be a distressing experience, and maybe quite frightening. This condition can also be easily defined because of its name:

  • ‘Paroxysmal‘; an incidence of symptoms that appear suddenly and may reoccur
  • ‘Nocturnal’; about
  • ‘Dyspnea’; a  medical term that refers to uncomfortable breathing, shortness of breath, or breathlessness.

PND is a general term for any condition that causes sudden shortness of breath which normally reoccurs after some relief, accompanied by coughing.


Paroxysmal nocturnal dyspnea may be caused by mechanisms similar to those for orthopnea. There is an inability in the left ventricle and suddenly the failing left ventricle is unable to match the output of a more normally functional right ventricle. 

The condition develops pulmonary congestion which results in shortness of breath and gasping for air. About 90 percent of all dyspnea cases are due to a lung or heart condition.

Heart Dysfunction

Paroxysmal dyspnea, as well as orthopnea, are specific symptoms of heart failure. Heart failure occurs when the heart encounters difficulty in pumping blood throughout the body. 

When the heart stops working normally, the body produces rennin, an enzyme that triggers fluid and sodium retention. This may lead to swelling if the heart is not able to handle the extra fluid. 

The build-up in the lungs (pulmonary edema), then causes shortness of breath. Some heart conditions that may cause PND to include:

Lung Conditions

Some respiratory conditions that lead to PND include:

Other Causes

Other health abnormalities that may cause paroxysmal dyspnea to include:


Common symptoms of PND include:

  • Waking up after few hours of sleep to gasp for air.
  • Coughing amidst shortness of breath after waking up.
  • Insomnia
  • Sleep anxiety
  • Symptoms may relieve in a sitting position.

A person may also experience symptoms of the underlying condition that causes their PND.


The risk of developing heart or lung conditions is a risk of developing paroxysmal nocturnal dyspnea.

Risk factor for heart failure may include:

  • High blood condition
  • A previous heart condition
  • Coronary heart disease
  • High cholesterol in the blood
  • Obesity
  • Diabetes
  • Use of tobacco and alcohol
  • Insufficient exercises
  • An unhealthy diet

Risk factors for lung disease include:

  • Tobacco smoking
  • Air pollutants
  • Allergens


A diagnosis for paroxysmal dyspnea is better done by diagnosing the underlying cause or causes. 

Diagnostic tests may include a combination of:

  • Physical exams, including:
  • Blood pressure tests
  • Weight measurements
  • Listening to a patient’s heart and lungs
  • Blood tests for
  •  Sodium levels
  • Potassium levels
  • Albumin levels
  • Creatinine  levels
  • Levels of certain biomarkers in the blood.
  • Chest X-rays, to know the enlargement and congestion of the lungs.
  • ECGs, to know the rhythm and frequency of heartbeat, and the heart electrical activity.
  • Echocardiography to assess the heart’s structure, and how well it pumps.
  • Radionuclide ventriculography or multiple-gated acquisition scanning.
  • Cardiac catheterization.
  • Magnetic resonance imaging (MRI) scan.
  • Exercise stress tests, to measure how patients’ heart responds to being put under pressure through exercise.


Treatment is dependent on the cause.

Heart Failure

Lifestyle changes, such as:

  • Stopping smoking
  • Moderating your weight
  • Eating a healthy and nourishing diet

Apply medications, may include:

  • Angiotensin-converting enzyme inhibitors
  • Angiotensin 11 receptors blockers
  • If channel blockers
  • Beta-blockers

Surgery or special implantation devices

Lungs Conditions

  • Asthma medication
  • Using a continuous positive airway pressure (CPAP) machine

Acid Reflux

  • A lifestyle changes
  • Antacids

Other treatments are focused on reducing stress and improving the overall quality of your sleep.

  • Avoid caffeine
  • Avoid or reduce alcohol intake
  • Adopt a quality of your sleep

CAUTION: Remember to seek emergency medical attention if you experience severe or ongoing shortness of breath or chest pain.


  • What causes paroxysmal nocturnal dyspnea?

Paroxysmal nocturnal dyspnea may be caused by mechanisms similar to those for orthopnea. The failing left ventricle is suddenly unable to match the output of a more normally functioning right ventricle, this results in pulmonary congestion.

  • How is paroxysmal nocturnal dyspnea diagnosed?

A PND can occur due to respiratory and cardiac conditions, a healthcare professional will want to diagnose the underlying cause. 

Diagnostic tests may include a combination of physical exams including blood pressure tests, weight measurements, and listening to a person’s heart and lungs.

  • What causes orthopnea?

Orthopnea is caused by increased pressure in the blood vessels of your lungs. When you lie down, blood flows from your legs back to your heart and then to your lungs. In healthy people, this redistribution of blood doesn’t cause any problems.

  • Why do I feel out of breath when I lay down pregnant?

Shortness of breath and difficulty breathing while laying down may be due to the mechanical effect of the enlarging uterus as the pregnancy progresses, causing the heart to sit higher in the chest.

  • What is the life expectancy of someone with diastolic heart failure?

Although there has been recent improvement in congestive heart failure treatment, researchers say the prognosis for people with the diseases is steel bleak, with about 50% having an average life expectancy of fewer than five years. For those with advanced forms of heart failure, nearly 90% die within one year.